Biometric identification methods are ubiquitous and have been employed in many areas as a means of ensuring security through personal verification. Established biometric identification methods include the use of fingerprints, hand geometry, iris, retina, voice recognition, handwriting, etc. The prior art identifies limitations to the reliable use of some of these methods due to difficulty acquiring the necessary details to make correct verifications, or due to logistical problems in employing the method of verification in the same manner each and every time.
Wadia (U.S. Pat. No 4,720,869) and Sidlauskas (U.S. Pat. No 4,736,203) have explored the use of hand surface geometry for the purpose of biometric identification. Wadia's use of a two-dimensional optical scanner to process the data to develop invariable hand measurements, and Sidlauskas' use of a digitizing camera and a pair of orthogonal reflecting surfaces to obtain a three-dimensional image of a hand have both been successful methods for identification. However, since the application of these methods rely on the soft-tissue dimensions of the hand, these methods are limited by the potential environmental and physiological factors that may alter the dimensions of the surface of the hand. Moreover, trials with this methodology have revealed that it is possible to falsify authentication.
Traditionally, plain radiographs, CT, and MRI have been used to evaluate the hand and wrist. However, recent advances in technology have allowed ultrasound to be considered one of the first line imaging techniques in the assessment of this entity. Ultrasound is an attractive option to analyze bone geometry because it is inexpensive, non-invasive, rapid and lacks the radiation exposure that often accompanies the traditionally preferred modalities.
Accordingly, there is a need for a method for biometric identification using ultrasound.